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Besiege: build a siege engine and test it to destruction
Besiege is a physics sandbox builder from Spiderling Studios where you bolt a medieval war machine together from a handful of beams, wheels, springs, saw blades and fuel canisters, then watch whether it survives contact with reality. There are no ready-made tanks or cannons here — only parts and the laws of physics. Want a catapult? Build the frame, attach a throwing arm, balance the counterweight. Want a striding monster on saws? Go ahead, but don't be surprised if it folds into a pile of debris on its very first step. It's this honest, unforgiving physics that makes Besiege a puzzle game, a sandbox and an endless source of hilarious failures all at once.
What kind of game it is
Every campaign level is an engineering problem with a single goal: bring down a fortress, crush a regiment of infantry, carry a fragile cargo across a chasm, or simply wipe everything off the map. You invent the solution yourself. The game never points to the “correct” machine — it just hands you parts and honestly simulates what happens when you hit the button. One player clears a level with a heavy battering ram, another with a light bomber plane, a third with an absurd centipede that wins against all common sense. That's the joy: there are dozens of valid answers, and half the fun is the road to them paved with spectacular explosions and collapsing contraptions.
Campaign, sandbox and editor
Besiege stands on three pillars. The first is the story islands with dozens of levels of rising difficulty: you start with a simple “break the gate” and end up storming fortified castles guarded by ballistae and patrols. The second is the sandbox mode with no objectives at all — just you, open terrain and a full crate of parts to build whatever you like. The third is a powerful machine editor: blocks snap together, control keys are mapped, and you tune the speed, power and behaviour of every joint. Anything you build can be saved and rebuilt endlessly.
Honest physics as the core mechanic
Everything in Besiege is simulated: mass, balance, joint strength, recoil, inertia. Overload a wing and the plane spins out. Make an arm too long and the catapult snaps from its own swing. That's not a bug, it's the point: you don't just build, you learn to think like an engineer through trial, error and controlled chaos. That's why Besiege lands equally well with people who love thoughtful mechanical puzzles and with those who just came to blow things up and laugh at the physics.
Platforms and Steam Deck
Besiege has left its long early access period and is now available as a full release with native builds for Windows, macOS and Linux. On Steam Deck it runs through the Proton compatibility layer, so you can keep building machines on the go. It isn't demanding on hardware — what matters is a CPU that can handle the physics when your hundred-part contraption finally bursts apart.
What you get and how the gift arrives
You're buying the base game Besiege as a Steam gift. It's a full copy with the entire campaign, sandbox and editor, and it stays on your account for good. The naval expansion “The Splintered Sea”, with its water physics, submarines and separate 15-level campaign, is not part of this lot — that's a standalone DLC you can buy separately if you want it.
Delivery goes through a bot. You provide your Steam friend invite link and your account region, the bot adds itself to your friends, sends the gift and leaves once it's delivered — you don't need to accept the request, and Steam Guard isn't required for this. The whole thing usually takes a couple of minutes. Two conditions matter, or Steam won't accept the gift: your account region must match the gift region, and you must not already own Besiege. So pick the variant that matches your Steam region.
Who it's for
Besiege is for anyone who loves construction toys, physics sandboxes and engineering puzzles where you devise the solution yourself. If you enjoy building ridiculous machines and watching them either triumphantly flatten a castle or collapse picturesquely, you're in the right place. Look for the same mood in Scrap Mechanic and Trailmakers — also about assembling vehicles from blocks — and for honest physics-based destruction check out Teardown.